In magnetic recording, as one example of a type of recording in which reading and writing are performed by a head that moves relative to the surface of the storage medium, data may be written in circular (or sometime spiral) tracks on a magnetic disk. In many magnetic recording systems, minimum track pitch is limited by the write head width, while the read head is designed to be narrower than the write head so that reading can occur without picking up signals from any adjacent track. In addition, guard bands—empty bands on either side of each track—are provided to help prevent data on one track from being overwritten during writing of an adjacent track because of write head positioning errors.
In other magnetic recording systems, in order to increase recording densities, it is desirable to shrink the track pitch and reduce or remove the guard bands between the tracks, which allows more tracks to fit on the recording medium. For example, in “Two-Dimensional Magnetic Recording,” also known as “Shingled Magnetic Recording” or “Shingle Write Recording,” the tracks are written so that one track partially overlaps the previous track. In such a system, track pitch theoretically may be arbitrarily small.